Florida State University senior Jason Derfuss said at first he didn't want to accept that he'd just heard a gun fired right behind him.
But as the 21-year-old was exiting Strozier Library about 12:25 a.m. Thursday, he knew what the "loud bang" was.
So Derfuss said he turned around very slowly and saw all the proof he needed — an image of the silent gunman firing two point-blank shots and a person crumpling to the ground, the Tallahassee Democrat reported. The shooter went on to wound two other FSU students before police fatally shot him.
Derfuss said he ran for his life, got in his car, and drove off. "I called my dad, who calmed me down," he told the Democrat. "And he told me to call 911, so I did."
After Derfuss gave his statement to police, he was finally back in the off-campus residence he shares with three other students just after 3 a.m. — and made an astonishing discovery.
More from the Democrat:
Derfuss had gone to the library about 9:15 p.m. that night to check out books he needed for a paper due the next day for his Christian Tradition class and do some last-minute research. He checked out a few books, including "John Wyclif (Great Medieval Thinkers)," about the 14-century philosopher, and stacked them in his backpack.
He dumped out his backpack on the floor and noticed two books for his research project were "completely messed up." In fact, it looked almost as if a bullet had torn through them.
Sure enough, one of his roommates found a slug lodged in the bottom of Derfuss' backpack, the Democrat reported.
"It was hard to wrap my mind around," he told the paper. "I've been told multiple times that those books shouldn't have stopped the bullet. And I honestly think this was a direct intervention by God."
What's more, the order of unfolding events told Derfuss that he was, in fact, the shooter's first target, the paper noted.
"It was humbling to know that my life was in God's hands right there and that he graciously spared me," he added to the Democrat, offering more thanks to God that "all of the victims are actually alive right now."
Check out Derfuss' interview with the Democrat: